Weather in Seoul Keep in mind the Seoul climate when packing. You will be arriving in the middle of the summer period, which is very hot and steamy especially June through September. In addition, you may have some dust storms impacting the air quality. And before you head home, you will experience some of the Winter in Korea, which you will need warm-weather clothes and an all-weather coat with a zip-in lining. For current and projected weather conditions in Seoul, visit www.weather.com or another reliable source for worldwide weather.